The progression of energy industry towards development, has made it highly susceptible to cyberattacks. X-Force Threat Intelligence Index 2023 has observed that in 2022 energy sector encountered 10.7% of the recorded cyberattacks. As the deployment of renewable energy sources expands, there is a growing focus on harnessing these emerging resources. In 2022, three wind energy businesses based in Europe encountered a breach of security that resulted in the temporary disruption of remote-control systems for around 5800 wind turbines, lasting for a duration of approximately one day. It is anticipated that there would be a rise in such attacks in the foreseeable future. Potential sources of cyber threats include various entities such as organised gangs employing ransomware as a means of financial gain, cybercriminals with affiliations to nation states seeking to damage crucial infrastructure or societal functions, as well as independent hostile hackers. The scope of these attacks extends beyond the essential infrastructure of nations, encompassing the intricate supply networks and widespread infrastructure of renewable energy organisations. Furthermore, the growing spread of assets and dependence on digital solutions by renewable energy firms significantly amplifies the vulnerability to cyber-attacks. This paper extensively examines the multifaceted legal challenges confronting the critical energy infrastructure (CEI) and reviews the regulatory framework pertaining to cybersecurity in the energy sector. Furthermore, the paper deliberates into the discourse on Article 2 (4) of the United Nations Charter, 1945 wherein cyber technology has been included within the domain of use of force. It also examines the circumstances under which specific types of cyber-attacks may warrant the invocation of the right to self-defence. Additionally, it considers other remedies that exist beyond the scope of Article 51 of the United Nations Charter. Therefore, the paper evaluates the intricate interdependencies within the energy sector and cyber security through an understanding of its intersectoral and cross-border dimensions.